Reduction of blood oxygen affinity in dogs by infusion of glycolytic intermediates

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Abstract
An i.v. infusion of 0.175 M dihydroxyacetone, 0.10 M disodium hydrogen phosphate and 0.10 M sodium pyruvate was administered at a rate of 20 ml/kg per h for 2 h to 4 adult Labrador retrievers (DDP group). Another 4 dogs (DDAP group) received identical treatment except that 3.75 mM adenine was added to the infusion. A control group was infused with normal saline at the same rate. Infusion produced hemodilution at 2 h, but mean corpuscular Hb concentration fell only slightly, indicating rapid equilibration of the infused materials across the red cell membrane. No change in P50 [O2 tension at 50% Hb concentration, 37.degree. C, pH 7.4] or 2,3-diphosphoglycerate (2,3-DPG) concentration was evoked by the saline infusion. At the end of the 2 h infusion, P50 had risen significantly in both the DDAP and DDP groups, and the increases were accompanied by significant elevations of 2,3-DPG. Twenty-four hours later P50 and 2,3-DPG concentrations remained elevated. No significant changes in ATP occurred as a result of these infusions. No toxic effects were observed. A rapid decrease in blood O2 affinity can be produced in dogs by i.v. infusion of dihydroxyacetone, pyruvate and phosphate. Reduction of blood O2 affinity may be of value in improving O2 supply to ischemic tissues.